It's stressful enough getting calls from debt collectors for bills you actually owe. (consumer.ftc.gov)
You might get calls and letters from another debt collector trying to collect the full balance on the account that you've already partially paid. (lendedu.com)
When you are faced with harassment from a debt collector, it is best to stay calm, be professional and polite, and keep records of everything, then contact an attorney. (westopdebtcollectors.com)